loss of power

[auto4life]

hey how yall doing. this is my first time posting on the site and i have a technical question
I've got an '85 2.8l 2wd 5 sp duel tank non a/c ranger that loses horsepower intermitantly but mostly during acceleration. does anybody have any suggestions on where i should look first? what are the common power related failures on this vehicle.

 

[Eric Kropp]

When you say "loses power". Does that mean that you are accelerating and it will start slowing noticably while accelerating? Or would you say it just accelerates like a pig? Does it seem to "miss" at all while accelerating? My first check would be the fuel filter on the carb. Second would be to make sure the fuel pump is getting enough fuel to the engine, and move on from there.

Eric

 

[skippy]

Incorrect timing,excessive play in distributor shaft,damaged rotor,faulty cap or wires,faulty or incorrectly gapped plugs,faulty coil,carb incorrectly adjusted or fouled,dragging brakes,clutch slipping,fuel filter,emmisions system,low or uneven compression.

Just a few ideas to get you started.

 

[auto4life]

by low power i mean it accelerates ok then it almost seems like the exhaust pluggs up. you can hear the engine lug more and more but there is no misfire. letting off the gas for a short time sometimes helps but not always which leads me to believe its not fuel delivery (pump) related and if i mash the petal to the floor it lugs hard for a bit then straitens up and runs ok till the next time this happends. i've checked out the ignition on an o- scope and the secondary ignition appears ok while not under load but my extension cord isnt long enough to test drive it with the scope hooked up
anyhoo i'll try out some of your suggestions and post the results
thanks for the help
jake

 

[Original_Ranger84]

Your cat. may be clogged if it seems like the exhaust is clogged. But I think it would be more continuous power loss...

Is your Air filter clean? ...

 

[auto4life]

i tried it without the air filter and it still does it... exhaust back pressure never gets above 2 psi with a gauge in the O2 sensor port... its free flowing. i'm fairly certain its an electrical problem.the distributor isn't loose, cap rotor plugs and ignition wires are new and scope out ok. is there a common problem on these trucks other than the ecm ground that might cause it? i've got a 10gauge wire running from the battery ground to the ecm mount to ensure a solid ground. i also tried disconnecting and plugging the egr to see if it might be an over active egr valve causing the problem.
i know these engines will scream if theyre tuned right. i've got the same engine in a '77 toyota dolphin RV

 

[enginepaul]

If you have factory smog - and it sounds like you might - pull the codes

 

[Original_Ranger84]

Hmmm. well then yeah all I can think I would be is your wireing or a vaccum leak... Wait did somebody already say fuel filter? might not be getting enough fuel in the higher rpms?